<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box {
            width: 100px;
            height: 100px;
            border: 1px solid #000;
            /* 属性名 过渡时间(200-300ms) 过渡方式(linear线性, ease先快后慢) 延迟时间 */
            transition: all 200ms ease;
            /* background-color: rgb(255, 0, 0); */
        }

        .box:hover {
            /* background-color: rgb(0, 128, 0); */
            box-shadow: 0 0 10px #000;
            width: 200px;
            /* height: 200px; */
        }

    </style>
</head>
<body>
    <div class="box"></div>
</body>
</html>